R22 vs R438A Refrigerant Comparison — Pressure, GWP, Safety
| Spec | R22 | R438A |
|---|---|---|
| Type | HCFC | HFC Blend |
| GWP | 1,810 | 2,265 |
| Ozone Depletion | 0.055 | 0 |
| Safety Class | A1 | A1 |
| Boiling Point | -41.4°F | -47°F |
| Critical Temp | 204.8°F | 185°F |
| Status | Phased out | AIM Act phase-down |
Key Differences
R22 GWP 1,810 vs R438A GWP 2,265
Advantage: R22
R22 operates at standard pressures; R438A at standard pressures
R22: ASHRAE A1 (non-flammable); R438A: ASHRAE A1
Recommendation
R22 has a lower GWP (1,810) compared to R438A (2,265). For new equipment purchases, R22 is the more future-proof choice given AIM Act HFC phase-down requirements. For retrofit/drop-in replacement in existing systems, consult the manufacturer's approved refrigerant list before switching.
Never mix refrigerants in a system. Mixing causes unpredictable pressure-temperature behavior, oil contamination, and potential acid formation. Always recover all refrigerant before switching types. Systems designed for R-22 typically require oil changes and component verification before accepting HFC alternatives.
Purchase and handling of refrigerants in containers larger than 2 lbs requires EPA Section 608 certification (Type I, II, or Universal depending on equipment type). Intentional venting of any refrigerant to atmosphere is illegal under the Clean Air Act.
Before substituting one refrigerant for another, verify: (1) compressor oil compatibility — POE oil required for most HFCs; (2) metering device adjustment — TXVs may need rerating; (3) system pressure ratings — some alternatives operate at higher pressures; (4) material compatibility — elastomers, gaskets, and seals must be rated for the new refrigerant.